Make your own free website on



    This simple device allows you to control electronic devices by opening or closing the external feeding circuit of 440 W. 

     This is done by a latch-type relay inside the white brick, that opens or closes the circuit of the plug with a signal from the RCX. If the applyed tension is positive +(2,7), the circuit closes and stays closed. However, if the tension is negative, the circuit opens

        By complementing this device with a special software (comming soon), you get something like a "Smart House System", being able to control different electric devices such as a microwave oven, a refrigerator or the lights of the house.

        The only thing you need to build the Magic Control is a latch type relay with 5V or 6 V bobine tension.and as much intensity capability as possible. Mine is actually a 5V latch relay that handles 2 A. Good luck and be careful!

[ The information used to build this device was obtained from ]

¿Would you like to control 6 motors and 3 sensors? ¿Or 5 sensors and 4 motors? ¿Or 7 sensors y 2 motors? This diagram explains how to do this using the RCX Expander 1.0:

6 motors - 2 sensors
2 motors - 7 sensors
4 motors - 5 sensors